In 5.1 they removed the operator "execute_node_group", which renders the custom node-groups in the Generate tab in Edit Mode unusable.
AttributeError: 'NoneType' object has no attribute 'name' and no __dict__ for setting new attributes
01:00.297 bpy.rna | ERROR Python script error in OBJECT_MT_MenuECut.draw
UILayout.operator(): unknown operator 'geometry.execute_node_group'
In 5.1 they removed the operator "execute_node_group", which renders the custom node-groups in the Generate tab in Edit Mode unusable.
similar issue
changelog 5.1